<template>
  <div class="article-container">
    <!-- 导航栏 -->
    <van-nav-bar
      class="page-nav-bar"
      left-arrow
      title="黑马头条"
    ></van-nav-bar>
    <!-- /导航栏 -->

    <div class="main-wrap">
      <!-- 加载中 -->
      <div
        class="loading-wrap"
        v-if="isLoading"
      >
        <van-loading
          color="#3296fa"
          vertical
        >加载中</van-loading>
      </div>
      <!-- /加载中 -->

      <!-- 加载完成-文章详情 -->
      <div
        class="article-detail"
        v-else-if="articles.title"
      >
        <!-- 文章标题 -->
        <h1 class="article-title">{{articles.title}}</h1>
        <!-- /文章标题 -->

        <!-- 用户信息 -->
        <van-cell
          class="user-info"
          center
          :border="false"
        >
          <van-image
            class="avatar"
            slot="icon"
            round
            fit="cover"
            :src="articles.aut_photo"
          />
          <div
            slot="title"
            class="user-name"
          >{{articles.aut_name}}</div>
          <div
            slot="label"
            class="publish-date"
          >{{articles.pubdate | dateFormat}}</div>
          <user-followed
            :autId='articles.aut_id'
            v-model="articles.is_followed"
          ></user-followed>
          <!-- v-model 是双向绑定的  如何解析的  即可以在表单使用  又可以在组件上使用
          什么时候使用：既要传值 又要改变数据
          解析两个东西 一个是值 另外一个是事件
          1-   值----    :value="articles.is_followed"
          2-   事件---  @input="articles.is_followed=$event"
           -->
        </van-cell>

        <!-- /用户信息 -->

        <!-- 文章内容 -->
        <div
          class="article-content"
          v-html="articles.content"
          ref="content"
        >这是文章内容</div>
        <van-divider>正文结束</van-divider>
        <article-commment
          :list='list'
          @updateTotal='totalCount=$event'
          :source="articles.art_id"
          @click-reply="clickReplyFn"
        ></article-commment>
      </div>
      <!-- /加载完成-文章详情 -->

      <!-- 加载失败：404 -->
      <div
        class="error-wrap"
        v-else-if="is404"
      >
        <van-icon name="failure" />
        <p class="text">该资源不存在或已删除！</p>
      </div>
      <!-- /加载失败：404 -->

      <!-- 加载失败：其它未知错误（例如网络原因或服务端异常） -->
      <div
        class="error-wrap"
        v-else
      >
        <van-icon name="failure" />
        <p class="text">内容加载失败！</p>
        <van-button
          @click="loadArticleInfo"
          class="retry-btn"
        >点击重试</van-button>
      </div>
      <!-- /加载失败：其它未知错误（例如网络原因或服务端异常） -->
    </div>

    <!-- 底部区域 -->
    <div
      class="article-bottom"
      v-if="articles.title"
    >
      <van-button
        class="comment-btn"
        type="default"
        round
        size="small"
        @click="writeComment"
      >写评论</van-button>
      <van-icon
        name="comment-o"
        :badge="totalCount"
        color="#777"
      />
      <article-collected
        :articleId='articles.art_id'
        v-model="articles.is_collected"
      ></article-collected>
      <article-setlike
        :articleId='articles.art_id'
        v-model="articles.attitude"
      ></article-setlike>

      <van-icon
        name="share"
        color="#777777"
      ></van-icon>
    </div>
    <!-- /底部区域 -->
    <!-- 回复文章评论的弹层 -->
    <van-popup
      v-model="isShowCommentPop"
      position="bottom"
    >
      <ArticlePost
        :target='articleId'
        @onPostSuccess='onPostSuccess'
      ></ArticlePost>
    </van-popup>
    <!-- 回复评论的弹层 -->
    <van-popup
      v-model="isShowReplyCommentPop"
      position="bottom"
      style="height:100%"
    >
      <ReplyPost
        :comment='comment'
        @closePop='isShowReplyCommentPop=false'
        v-if="isShowReplyCommentPop"
      ></ReplyPost>
    </van-popup>
  </div>
</template>

<script>
import { getArticleInfo } from '@/api/article.js'

// 按需引入 ImagePreview
import { ImagePreview } from 'vant'
import UserFollowed from '@/components/user-followed.vue'
import ArticleCollected from './components/article-collected.vue'
import ArticleCommment from './components/article-comment.vue'
import ArticlePost from './components/article-post.vue'
import ReplyPost from './components/reply-post.vue'
import ArticleSetlike from './components/article-setlike.vue'

export default {
  name: 'articles',
  props: {
    // 路由接手的文章ID
    articleId: {
      type: String
    }
  },
  data () {
    return {
      // 文章信息存储对象
      articles: {},
      // 是否加载中
      isLoading: false,
      is404: false,
      totalCount: 0,
      // 控制文章评论pop弹出层的显示和隐藏变量
      isShowCommentPop: false,
      // 控制评论的评论pop弹出层的显示和隐藏变量
      isShowReplyCommentPop: false,
      // 存放评论的数组
      list: [],
      // 当前的评论对象
      comment: {}

    }
  },
  methods: {
    // 加载文章信息
    async loadArticleInfo () {
      this.isLoading = true
      try {
        const res = await getArticleInfo(this.articleId)
        this.articles = res.data.data
        console.log(this.articles)

        // this.$toast.success('获取成功')
        this.isLoading = false
        // 成功的页面才会调用图片预览处理函数
        this.previewImg()
      } catch (err) {
        // 判断是否404错误
        if (err.response && err.response.status === 404) {
          this.is404 = true
        }
        this.$toast('获取失败')
        this.isLoading = false
      }
    },
    previewImg () {
      // 视图dom更新是异步的
      this.$nextTick(() => {
        // 获取所有的图片
        const imgs = this.$refs.content.querySelectorAll('img')
        // 所有的图片地址 数组
        const images = []
        imgs.forEach((item, index) => {
          // 把每一张图片的src地址保存到images数组中
          images.push(item.src)
          // 为一张图片添加点击事件  事件处理函数为 ImagePreview 插件
          item.onclick = function () {
            ImagePreview({
              images,
              startPosition: index
            })
          }
        })
      }
      )
    },
    // 打开写评论弹窗
    writeComment () {
      this.isShowCommentPop = true
    },
    // 文章评论视图更新
    onPostSuccess (e) {
      // list追加数据到前面
      this.list.unshift(e)
      // 关闭弹窗
      this.isShowCommentPop = false
    },
    // 评论文章处理函数
    clickReplyFn (e) {
      // 显示弹窗
      this.isShowReplyCommentPop = true
      // 保存数据
      this.comment = e
    }

  },
  computed: {},
  watch: {},
  filters: {},
  components: {
    UserFollowed,
    ArticleCollected,
    ArticleCommment,
    ArticleSetlike,
    ArticlePost,
    ReplyPost
  },
  created () {
    this.loadArticleInfo()
  },
  mounted () { }
}
</script>

<style scoped lang="less">
.article-container {
  .main-wrap {
    position: fixed;
    left: 0;
    right: 0;
    top: 92px;
    bottom: 88px;
    overflow-y: scroll;
    background-color: #fff;
  }
  .article-detail {
    .article-title {
      font-size: 40px;
      padding: 50px 32px;
      margin: 0;
      color: #3a3a3a;
    }

    .user-info {
      padding: 0 32px;
      .avatar {
        width: 70px;
        height: 70px;
        margin-right: 17px;
      }
      .van-cell__label {
        margin-top: 0;
      }
      .user-name {
        font-size: 24px;
        color: #3a3a3a;
      }
      .publish-date {
        font-size: 23px;
        color: #b7b7b7;
      }
      .follow-btn {
        width: 170px;
        height: 58px;
      }
    }

    .article-content {
      padding: 55px 32px;
      /deep/ p {
        text-align: justify;
      }
    }
  }

  .loading-wrap {
    padding: 200px 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fff;
  }

  .error-wrap {
    padding: 200px 32px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: #fff;
    .van-icon {
      font-size: 122px;
      color: #b4b4b4;
    }
    .text {
      font-size: 30px;
      color: #666666;
      margin: 33px 0 46px;
    }
    .retry-btn {
      width: 280px;
      height: 70px;
      line-height: 70px;
      border: 1px solid #c3c3c3;
      font-size: 30px;
      color: #666666;
    }
  }

  .article-bottom {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    box-sizing: border-box;
    height: 88px;
    border-top: 1px solid #d8d8d8;
    background-color: #fff;
    .comment-btn {
      width: 282px;
      height: 46px;
      border: 2px solid #eeeeee;
      font-size: 30px;
      line-height: 46px;
      color: #a7a7a7;
    }
    .van-icon {
      font-size: 40px;
      .van-info {
        font-size: 16px;
        background-color: #e22829;
      }
    }
  }
}
</style>
